Electronic devices and other apparatuses, such as wearable devices like smart watches, heart rate monitors, or fitness monitors, may be attached to one or more body parts of a user utilizing attachment structures such as bands. To meet various fitting requirements, it is preferred that wearable bands are adjustable in terms of length. It is also preferred that wearable bands can automatically adjust the band length to maintain desired tightness during wearing. It is further preferred that wearable bands, especially those to be worn on a wrist or arm, require very simple one-handed operation. Most preferable would be a wearable band that required no use of the opposite hand other than to position or place the object on the desired location after which the band is capable of completing the attachment by itself automatically as a hands free operation.
Conventional bands include expanding linkages and non-expanding linkages. Conventional bands, such as watch bands, jewelry bands, magnetic health bands, bracelets, and necklaces, however, often are very delicate and flimsy and do not hold up well to physical exercise, fitness activities and sports.
Most conventional bands use clasps to open and close bands. Traditional clasp mechanisms come in various forms. Buckle and strap clasp mechanisms rely on mechanical features to keep the band or flap closed. Buckle and strap mechanisms can provide one-handed operation and can be adjusted, but they are not easy to use in one handed operation. Hook and loop clasps, such as Velcro-like fasteners can be adjusted and open or closed by one hand, but they are not aesthetically pleasing. Button and hole clasps can be adjustable if there are multiple holes, but they are difficult to operate one-handed and the length adjustment is limited by the locations of the holes. Magnetic closure mechanisms use a post and hole configuration for alignment of the magnetic closure for mechanical retention in shear. Such magnetic closures are operable by one-hand but have limitations.
Generally, conventional bands with clasps provide very limited flexibilities for users to adjust and obtain the most comfortable tightness for the straps when the bands are put on a body part. None of those bands can further automatically adjust the fitting of the bands which may become loose or tight during wearing as a result of a person's daily activities.
There is still a need to provide an improved wearable band which is adjustable in length and suitable for one handed or even hands free operation. Desirably, the wearable band is able to clasp automatically upon putting onto a body. It would also be desirable for the wearable band to be able to automatically adjust the tightness of the band immediately after clasping and also during a course of daily activities.